Cutaneous angiosarcomas with a starry-sky pattern.

A subgroup of epithelioid angiosarcomas, which we have identified, has a prominent starry-sky histologic pattern. All these neoplasms were evaluated with routine histopathology and with immunohistochemical stains. Clinical follow-up was also obtained to determine whether these angiosarcomas' had any other distinctive properties.Histopathologic features and immunohistochemical stains, including cytokeratin, epithelial membrane antigen, CD34, LCA, factor VIII-related antigen, KP-1, vimentin, HMB-45, and S100 protein were performed on all four neoplasms.These angiosarcomas occurred on the extremities of patients with chronic edema as well as on the scalp of elderly patients.All patients were dead within 5 years of diagnosis. Of the three patients where angiosarcoma was listed as the cause of death, all were dead within 30 months.All tumors showed a similar immunohistochemical staining pattern. Vimentin, factor VIII-related antigen, and CD34 were positive in all tumors. The remaining immunohistochemical stains including cytokeratin, which may be positive in other epithelioid angiosarcomas, were negative.We present a distinctive starry-sky histologic pattern in epithelioid angiosarcomas. Knowledge of this pattern may be important in the early diagnosis of this rapidly fatal neoplasm.